Traditional mainframe computer configurations provided for user interface to the computer through computer terminals which were directly connected by wires to ports of the mainframe computer. As computing technology has evolved, processing power has typically evolved from a central processing center with a number of relatively low-processing power terminals to a distributed environment of networked processors. Examples of this shift in processing include local or wide area computer networks which interconnect individual work stations where each workstation has substantial independent processing capabilities. This shift may be further seen in the popularity of the Internet which interconnects many processors and networks of processors through devices such as, for example, routers. This type of network environment is often referred to as a client-server environment with client stations coupled to and supported by a server station.
In the modern distributed processing computer environment, control over software, such as application programs, is more difficult than where a mainframe operated by an administrator is used, particularly for large organizations with numerous client stations and servers distributed widely geographically and utilized by a large number of users. Furthermore, individual users may move from location to location and need to access the network from different client stations at different times. The networked environment increases the challenges for a network administrator in maintaining proper licenses for existing software and deploying new or updated applications programs across the network.
One approach to reducing software distribution and control problems is to use an application server in which the application programs are installed and maintained on a centralized server which supports a plurality of client stations (sometimes referred to as a client/server application as contrasted to a desktop application). In addition, the Systems Management Server (SMS) program from Microsoft Corporation provides an ability to transmit an application program from a server to a number of clients. The SMS system typically allows installation of programs and associated icons at client stations for SMS-enabled applications. A customized install generally must be created by a system administrator for each different version to be installed. Furthermore, once installed at a client, a user must typically use that specific client station. The application generally cannot be automatically deleted from the client station's desktop or automatically upgraded the next time the user starts the application. Similarly, the Tivoli Management Environment (TME) 10™ system from Tivoli Systems, Inc. provides a software distribution feature which may be used to transmit a file package to client and server stations on a network from a central Tivoli™ server.
A further complication in network systems is that, typically, these systems include combinations of network applications and native applications as well as combinations of different connection types and hardware devices. As used herein “native applications” refers to applications which are installed locally on a workstation such that characteristics associated with the native application are stored on the workstation. The combinations of network connections, differing hardware, native applications and network applications makes portability of preferences or operating environment characteristics which provide consistency from workstation to workstation difficult. Furthermore, differences in hardware or connections may create inefficiencies as users move from workstation to workstation. For example, a user may, in a first session, access the network utilizing a high speed connection and a workstation with a high resolution color monitor to execute an application and then, in a later session, access the network to execute the same application from a mobile computer with a monochrome display and a low speed modem connection to the network. Thus, session content, such as color display data or preferences associated with the application, which may have been appropriate for the first session may be inappropriate or inefficient in a later session.
Efforts to address mobility of users in a network have included efforts to provide preference mobility such as, for example, Novell's Z.E.N.works™, Microsoft's “Zero Administration” initiative for Windows® and International Business Machines Corporation's (IBM's) Workspace On Demand™. However, these solutions each typically require pre-installation of software at the workstation to support their services. For example, Novell's Z.E.N. and IBM's Workspace On Demand utilize a designer-supplied support layer in the operating system to enable their services. In addition to modifying the workstations operating system at startup to setup tasks to customize the user's environment, the Microsoft Zero Administration solution is typically limited to a homogeneous (Windows® only) environment where the workstation and the server are utilizing the same operating system.
Another approach to centralized management is the traditional mainframe model, such as with the IBM 3270 system, or an X Windows environment. However, in each of these approaches, the client device is treated as a dumb terminal with execution of the applications occurring at the server rather than the client. Accordingly, the communication between the server and the client is typically presenting characters for a display screen of the client and/or receiving key strokes from the client. Windows Zero Administration, as described above, is client rather than user oriented and installs applications on client stations which does not fully support roaming by users. The JAVA™ environment utilized on the Internet for web applications provides an ability for hardware independent application development but fails to provide an integrated framework for presenting multiple independent applications to a user. While various web applications, such as the Netscape Mission Control desktop, do allow personalizing of a specific application display by a user, this capability is generally not managed across applications for a user. Furthermore, it typically associates personalized screen information with an Internet address (and sometimes a “cookie” installed at the client) which is associated with a client device rather than a user, therefore limiting its ability to support roaming by users.
Each of these “mobility” systems typically do not address the full range of complications which may arise in a heterogeneous network utilizing differing devices and connections. The system typically will not present application choices associated with the user and for which the user is authorized but instead present information associated with the particular client workstation. Users would typically have to manually define session characteristics at each differing workstation they used in the network or maintain local characteristic definitions which may be inappropriate for particular applications a user is executing and may substantially reduced the administrative convenience of a centrally controlled network. Thus, these various approaches fail to provide a seamless integration of application access and session characteristics across heterogeneous networks. Such solutions may, at most, reduce network administration only after initial installation on each workstation. In addition, control over access by users is difficult to accomplish in a mobile environment.
Furthermore, these various approaches have, at most, only limited capabilities to provide a uniform framework for deployment of new or updated application programs from different software designers. To the extent software distribution capabilities from a central location are provided, such as with the TME 10™ system, they typically require various steps in the installation process to occur at different locations rather than allowing the entire process to be controlled from a single point for an entire managed network environment.